MTA employee Percillia Augustine-Soverall was saved by a good Samaritan, and by the subway booth’s Halon fireproofing system.

Cops Tuesday arrested a man who tried to set fire to a subway token booth during an attempted robbery that could have killed a horrified station agent who cowered inside when she saw the flames.

MTA worker Percillia Agustine-Soverall, 44, told the Daily News that she was sitting in the booth at the Nostrand Avenue station on the No. 3 line in Crown Heights Friday night when a robber “threw gasoline” into the booth’s small opening and demanded money.

“He said that if I didn’t give him the money, he would light me up,” she said.

That’s when he lit a rag or t-shirt soaked in gasoline to start the blaze around 10:30 p.m.

But the booth’s Halon system, which detects harmful substances, activated before the fire could spread, flooding the booth with white foam.

A good Samaritan knocked the shirt out of the man’s hand and stomped on it before the suspect fled.

“The system came on and then the whole booth was like, all you see is white,” Augustine-Soverall said. “Everything was just cloudy in the booth. I couldn’t do anything... I just started crying, I was in shock.”

Cops arrested Everette Robinson, 51, of St. Mark’s Avenue in Brooklyn Tuesday morning, and charged him with attempted robbery.

“This was an cowardly, evil act against a transit worker who was simply doing her job,” Transport Workers Union Local 100 President John Samuelsen said. “New York is able to work because we run the subways and buses every day. But our members face countless dangers, including arson attacks, while providing this vital public service.”

A token booth fire set by a robber killed a clerk in 1995. Cops said Harry P. Kaufman begged for his life after an attacker squirted a flammable liquid into a window opening at the Kingston-Throop Avenues subway station in Bedford-Stuyvesant.

Kaufman died two weeks later.

Prosecutors denied the gruesome attack was a copycat crime despite the depiction of such a scene in the popular movie, “Money Train,” which starred Woody Harrelson and Wesley Snipes.